Python FFT finding frequencies-Numpy

Question

Masood_786 -2 Newbie Poster

13 Years Ago

Hi All
i have downloaded following code from web that inputs sound samples and displays spectrum, i want to print frequencies present in each second in the spectrum.i.e
when ever the spectrum is displayed i want to print those frequencies as well on the console. Below is the code i am using i initially used "print fftx". Is "fftx" present in the code is frequency. Also how can i measure the amplitude of each frequency so as next step i will print three frequencies with the top most amplitude.
Thanks in advance.

import pyaudio
import scipy
import struct
import scipy.fftpack

from Tkinter import *
import threading
import time, datetime
import wckgraph
import math

#ADJUST THIS TO CHANGE SPEED/SIZE OF FFT
bufferSize=2**11
#bufferSize=2**8

# ADJUST THIS TO CHANGE SPEED/SIZE OF FFT
sampleRate=48100
#sampleRate=64000

p = pyaudio.PyAudio()
chunks=[]
ffts=[]
def stream():
global chunks, inStream, bufferSize
while True:
chunks.append(inStream.read(bufferSize))

def record():
global w, inStream, p, bufferSize
inStream = p.open(format=pyaudio.paInt16,channels=1,\
rate=sampleRate,input=True,frames_per_buffer=bufferSize)
threading.Thread(target=stream).start()

def downSample(fftx,ffty,degree=10):
x,y=[],[]
for i in range(len(ffty)/degree-1):
x.append(fftx[i*degree+degree/2])
y.append(sum(ffty[i*degree:(i+1)*degree])/degree)
return [x,y]

def smoothWindow(fftx,ffty,degree=10):
lx,ly=fftx[degree:-degree],[]
for i in range(degree,len(ffty)-degree):
ly.append(sum(ffty[i-degree:i+degree]))
return [lx,ly]

def smoothMemory(ffty,degree=3):
global ffts
ffts = ffts+[ffty]
if len(ffts) <= degree:
return ffty
ffts=ffts[1:]
return scipy.average(scipy.array(ffts),0)

def detrend(fftx,ffty,degree=10):
lx,ly=fftx[degree:-degree],[]
for i in range(degree,len(ffty)-degree):
ly.append(ffty-sum(ffty[i-degree:i+degree])/(degree*2))
#ly.append(fft-(ffty[i-degree]+ffty[i+degree])/2)
return [lx,ly]

def graph():
global chunks, bufferSize, fftx,ffty, w
if len(chunks)>0:
data = chunks.pop(0)
data=scipy.array(struct.unpack("%dB"%(bufferSize*2),data))
#print "RECORDED",len(data)/float(sampleRate),"SEC"
ffty=scipy.fftpack.fft(data)
fftx=scipy.fftpack.rfftfreq(bufferSize*2, 1.0/sampleRate)
fftx=fftx[0:len(fftx)/4]
ffty=abs(ffty[0:len(ffty)/2])/1000
ffty1=ffty[:len(ffty)/2]
ffty2=ffty[len(ffty)/2::]+2
ffty2=ffty2[::-1]
ffty=ffty1+ffty2
ffty=scipy.log(ffty)-2
#fftx,ffty=downSample(fftx,ffty,5)
#fftx,ffty=detrend(fftx,ffty,30)
#fftx,ffty=smoothWindow(fftx,ffty,10)
ffty=smoothMemory(ffty,3)
#fftx,ffty=detrend(fftx,ffty,10)
w.clear()
#w.add(wckgraph.Axes(extent=(0, -1, fftx[-1], 3)))
w.add(wckgraph.Axes(extent=(0, -1, 6000, 3)))
w.add(wckgraph.LineGraph([fftx,ffty]))
w.update()
if len(chunks)>20:
print "falling behind...",len(chunks)

def go(x=None):
global w,fftx,ffty
print "STARTING!"
threading.Thread(target=record).start()
while True:
graph()

root = Tk()
root.title("SPECTRUM ANALYZER")
root.geometry('500x200')
w = wckgraph.GraphWidget(root)
w.pack(fill=BOTH, expand=1)
go()
mainloop()

python

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Latest Post 13 Years Ago Latest Post by Masood_786

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bumsfeld 413 Nearly a Posting Virtuoso

13 Years Ago

Please use code tags with your code to preserve the indentations. Otherwise the code is very difficult to read and not too many folks will help.

[code]
your Python code here

[/code]

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Masood_786 -2 Newbie Poster · Answer 1 · 2011-01-23T21:58:53+00:00

Hi All
i have downloaded following code from web that inputs sound samples and displays spectrum, i want to print frequencies present in each second in the spectrum.i.e
when ever the spectrum is displayed i want to print those frequencies as well on the console. Below is the code i am using i initially used "print fftx". Is "fftx" present in the code is frequency. Also how can i measure the amplitude of each frequency so as next step i will print three frequencies with the top most amplitude.
Thanks in advance.

import pyaudio
import scipy
import struct
import scipy.fftpack

from Tkinter import *
import threading
import time, datetime
import wckgraph
import math

#ADJUST THIS TO CHANGE SPEED/SIZE OF FFT
bufferSize=2**11
#bufferSize=2**8

# ADJUST THIS TO CHANGE SPEED/SIZE OF FFT
sampleRate=48100
#sampleRate=64000

p = pyaudio.PyAudio()
chunks=[]
ffts=[]
def stream():
global chunks, inStream, bufferSize
while True:
chunks.append(inStream.read(bufferSize))

def record():
global w, inStream, p, bufferSize
inStream = p.open(format=pyaudio.paInt16,channels=1,\
rate=sampleRate,input=True,frames_per_buffer=bufferSize)
threading.Thread(target=stream).start()

def downSample(fftx,ffty,degree=10):
x,y=[],[]
for i in range(len(ffty)/degree-1):
x.append(fftx[i*degree+degree/2])
y.append(sum(ffty[i*degreei+1)*degree])/degree)
return [x,y]

def smoothWindow(fftx,ffty,degree=10):
lx,ly=fftx[degree:-degree],[]
for i in range(degree,len(ffty)-degree):
ly.append(sum(ffty[i-degree:i+degree]))
return [lx,ly]

def smoothMemory(ffty,degree=3):
global ffts
ffts = ffts+[ffty]
if len(ffts) <= degree:
return ffty
ffts=ffts[1:]
return scipy.average(scipy.array(ffts),0)

def detrend(fftx,ffty,degree=10):
lx,ly=fftx[degree:-degree],[]
for i in range(degree,len(ffty)-degree):
ly.append(ffty[i]-sum(ffty[i-degree:i+degree])/(degree*2))
#ly.append(fft[i]-(ffty[i-degree]+ffty[i+degree])/2)
return [lx,ly]

def graph():
global chunks, bufferSize, fftx,ffty, w
if len(chunks)>0:
data = chunks.pop(0)
data=scipy.array(struct.unpack("%dB"%(bufferSize*2),data))
#print "RECORDED",len(data)/float(sampleRate),"SEC"
ffty=scipy.fftpack.fft(data)
fftx=scipy.fftpack.rfftfreq(bufferSize*2, 1.0/sampleRate)
fftx=fftx[0:len(fftx)/4]
ffty=abs(ffty[0:len(ffty)/2])/1000
ffty1=ffty[:len(ffty)/2]
ffty2=ffty[len(ffty)/2::]+2
ffty2=ffty2[::-1]
ffty=ffty1+ffty2
ffty=scipy.log(ffty)-2
#fftx,ffty=downSample(fftx,ffty,5)
#fftx,ffty=detrend(fftx,ffty,30)
#fftx,ffty=smoothWindow(fftx,ffty,10)
ffty=smoothMemory(ffty,3)
#fftx,ffty=detrend(fftx,ffty,10)
w.clear()
#w.add(wckgraph.Axes(extent=(0, -1, fftx[-1], 3)))
w.add(wckgraph.Axes(extent=(0, -1, 6000, 3)))
w.add(wckgraph.LineGraph([fftx,ffty]))
w.update()
if len(chunks)>20:
print "falling behind...",len(chunks)

def go(x=None):
global w,fftx,ffty
print "STARTING!"
threading.Thread(target=record).start()
while True:
graph()

root = Tk()
root.title("SPECTRUM ANALYZER")
root.geometry('500x200')
w = wckgraph.GraphWidget(root)
w.pack(fill=BOTH, expand=1)
go()
mainloop()

Python FFT finding frequencies-Numpy

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